Anterior deltoid atrophy after reverse shoulder arthroplasty: a preliminary prospective study on surgical approach and neurophysiological correlates.

The risk of suprascapular and axillary nerve injury in reverse total shoulder arthroplasty: An anatomic study

Reverse total shoulder arthroplasty is an effective procedure to improve shoulder pain, range of motion, and function for a variety of conditions, including glenohumeral osteoarthritis and rotator cuff arthropathy. However, up to 22% of patients have persistent shoulder pain 12-24 mos after reverse total shoulder arthroplasty, even in the absence of surgical complications. Currently, there are no widely accepted nonpharmacological treatments for persistent postoperative pain after reverse total shoulder arthroplasty. This case report details the successful management of a 64-yr-old woman with chronic postoperative shoulder pain after reverse total shoulder arthroplasty. She was treated with single-lead percutaneous peripheral nerve stimulation to the right axillary nerve for 8 wks with 12 Hz motor-level stimulation. She demonstrated improvement in shoulder flexion active range of motion, shoulder flexion strength, and shoulder abduction strength. Her Shoulder Pain and Disability Index total score improved from 26.93% to 8.46% 1 yr after treatment. She reported an overall Global Rating of Change of +7 one year after treatment. This case's success demonstrates that short term peripheral nerve stimulation may provide long-term improvement of persistent postoperative pain and dysfunction in patients with painful reverse total shoulder arthroplasty.

What's New in Shoulder and Elbow Surgery.

Injury to the axillary and suprascapular nerves in rotator cuff arthropathy and after reverse shoulder arthroplasty: a prospective electromyographic analysis

What's New in Shoulder and Elbow Surgery.

Neurologic deficit after reverse total shoulder arthroplasty: correlation with distalization

Revision reverse shoulder arthroplasty has similar outcomes to primary reverse shoulder arthroplasty at 5 Year average follow-up

Nerve injuries are uncommon, yet significant complications following reverse total shoulder arthroplasty (rTSA), with the axillary nerve being most frequently injured. We report a case of a 67‐year‐old female who developed persistent motor dysfunction and decreased sensation in the axillary distribution following rTSA for a comminuted proximal humerus fracture. Electrodiagnostic studies confirmed right axillary nerve injury with reduced motor unit recruitment. After no improvement in deltoid function at three months following rTSA, we discussed treatment options for the patient, who opted for surgical intervention. Based on intraoperative findings, we performed a reverse end‐to‐side triceps‐to‐axillary nerve transfer. Postoperative evaluations over a four‐year follow‐up revealed substantial improvements in range of motion, strength, and patient‐reported outcomes. Ultrasound and magnetic resonance imaging studies obtained at four years post-op demonstrated mild deltoid atrophy and fatty infiltration, despite the excellent clinical result. The triceps‐to‐axillary nerve transfer has potential as a viable intervention for non-recovering axillary nerve injuries after rTSA.

The reverse total shoulder arthroplasty was introduced to treat the rotator cuff-deficient shoulder. Since its introduction, an improved understanding of the biomechanics of rotator cuff deficiency and reverse shoulder arthroplasty has facilitated the development of modern reverse arthroplasty designs. We review (1) the basic biomechanical challenges associated with the rotator cuff-deficient shoulder; (2) the biomechanical rationale for newer reverse shoulder arthroplasty designs; (3) the current scientific evidence related to the function and performance of reverse shoulder arthroplasty; and (4) specific technical aspects of reverse shoulder arthroplasty. A PubMed search of the English language literature was conducted using the key words reverse shoulder arthroplasty, rotator cuff arthropathy, and biomechanics of reverse shoulder arthroplasty. Articles were excluded if the content fell outside of the biomechanics of these topics, leaving the 66 articles included in this review. Various implant design factors as well as various surgical implantation techniques affect stability of reverse shoulder arthroplasty and patient function. To understand the implications of individual design factors, one must understand the function of the normal and the cuff-deficient shoulder and coalesce this understanding with the pathology presented by each patient to choose the proper surgical technique for reconstruction. Several basic science and clinical studies improve our understanding of various design factors in reverse shoulder arthroplasty. However, much work remains to further elucidate the performance of newer designs and to evaluate patient outcomes using validated instruments such as the American Society for Elbow Surgery, simple shoulder test, and the Constant-Murley scores.

Inadequate subscapularis repair has been advocated as one of the contributing factors for dislocation in reverse total shoulder arthroplasty; nonetheless the need to restore the subscapularis tendon integrity is under debate. The aim of this systematic review was to answer the question: does subscapularis reattachment following reverse total shoulder arthroplasty improve joint stability, range of motion and functional scores? The literature was systematically screened in accordance with PRISMA guidelines looking for papers evaluating clinical outcomes of reverse total shoulder arthroplasty in relation to the management of subscapularis tendon. Studies comparing clinical outcomes, complications and dislocation rate with or without subscapularis repair were included. Studies in which reverse total shoulder arthroplasty was performed for trauma or tumors were excluded. The methodology of included articles was scored with MINORS scale and the Risk of Bias was assessed adopting the ROBINS-I (Risk Of Bias In Non-randomized Studies of Interventions) developed by the Cochrane Group. A meta-analysis was also performed combining the studies to increase the sample size and hence the power to obtain meaningful data. The database search identified 1062 records, and 6 full-text articles were finally included. A total number of 1085 reverse total shoulder arthroplasty were assessed on. Except for one study, lateralized prosthetic designs have been used. Dislocation occurred in 0.8% (5/599 patients) of the patient with repaired subscapularis and in 1.6% (8/486 patients) of the tenotomized patients, and subscapularis repair was not associated with a higher risk of dislocation (pooled Peto OR: 0.496, 95% CI: 0.163 to 1.510, p = 0.217). Qualitative assessment revealed no differences in the range of motion and clinical scores. Subscapularis repair after reverse total shoulder arthroplasty produces no clinically meaningful benefits, particularly using lateralized prosthetic designs. Subscapularis re-attachment does not improve implant stability, nor increases range of motion or clinical scores. Given these results, keeping in mind the antagonistic effect of the repaired subscapularis on external rotation, no evidence lead to suggest subscapularis reattachment following reverse total shoulder arthroplasty with lateralized prosthetic designs.

The reverse total shoulder arthroplasty (RSA) is a widely used innovative procedure for managing shoulder pathologies like severe rotator cuff arthropathy, osteoarthritis with significant glenoid deformity, or proximal humerus fractures. RSA prosthesis designs utilize the deltoid muscle to bypass the role of the rotator cuff, and to generate most of the force required for shoulder elevation. As such, preoperative deltoid insufficiency or injury, as well as any intraoperative or postoperative complications involving the deltoid, can significantly impact patient outcomes, rehabilitation, and recovery following RSA. The aim of our review is to highlight the critical role of the deltoid muscle in RSA and discuss the different perioperative challenges that may impact its function and the overall success of the procedure. The PubMed/MEDLINE database was screened for studies describing or reporting peri-operative deltoid or axillary nerve pathologies in the setting of RSA, from database inception until August of 2023. Articles were excluded if animals subjects were involved, or if they were written in the non-English language. Relevant search terms were used, and additional articles were retrieved from the reference lists of included articles. Ensuring the health and integrity of the deltoid muscle is essential for obtaining successful RSA outcomes. At the preoperative stage, deltoid insults can occur due to imbalances in glenohumeral musculature, pre-existing axillary nerve injury and subsequent deltoid atrophy, and concurrent viral infections. Remaining vigilant regarding diagnosis is important at this stage, as surgical treatment should be delayed until symptomatic resolution occurs. Intraoperatively, deltoid injuries can occur due to significant retraction, dissection, or iatrogenic fractures or nerve injuries. Conducting periodic intraoperative axillary nerve assessments and utilizing intraoperative nerve monitoring allow surgeons to potentially intervene in order to help minimize nerve damage. Postoperatively, pathologies can occur due to deltoid fatigue or acromial stress fractures. At that stage, educating patients about potential setbacks is important to set appropriate expectations and minimize injury risk. Considering the importance of the deltoid in achieving proper RSA outcomes, significant attention should be garnered towards its integrity and health throughout the perioperative process.

The effect of subscapularis repair on dislocation rates in reverse shoulder arthroplasty: a meta-analysis and systematic review

BackgroundThe deltopectoral approach is a well-described surgical approach to the proximal humerus and glenohumeral joint. One of the structures at risk during this approach is the axillary nerve. Typically, the axillary nerve arises off the posterior cord of the brachial plexus and courses lateral to the proximal humerus and inferior to the glenohumeral joint, exiting the axilla through the quadrangular space. We describe a case of an aberrant axillary nerve, coursing anteriorly across the glenohumeral joint within the deltopectoral groove encountered during a reverse total shoulder arthroplasty.Case presentationA 73-year-old female presented complaining of atraumatic progressive right shoulder pain of several months duration. Clinical and radiographic findings were consistent with advanced rotator cuff arthropathy. After failing appropriate non-operative treatment, the patient elected to undergo reverse total shoulder arthroplasty. During the deltopectoral approach to the glenohumeral joint, the axillary nerve was found to be coursing deep to the cephalic vein within the deltopectoral interval. The nerve was isolated and protected, and the glenohumeral joint was accessed via a small window in the anterior deltoid muscle. The remainder of the procedure was performed without complication. The patient was found to be healing well and with normal axillary nerve function at 4-month follow-up.ConclusionsNeurologic lesions are well-documented complications of reverse total shoulder arthroplasty. The integrity of the axillary nerve is of particular importance to reverse total shoulder arthroplasty as it innervates the deltoid and post-operative function of the extremity is dependent upon a functioning deltoid muscle. Extreme care must be taken to avoid insult to the axillary nerve and any aberrant paths it may course around the glenohumeral joint.

Comparison of clinical outcomes of revision reverse total shoulder arthroplasty for failed primary anatomic vs. reverse shoulder arthroplasty

Reverse total shoulder arthroplasty is a common treatment for patients with rotator cuff arthropathy who have failed a prior rotator cuff repair. Latissimus dorsi transfer can be performed simultaneously to reverse total shoulder arthroplasty for patients with preoperative external rotation deficiency. Current literature is limited with several studies providing functional and pain improvements at short-term follow-up; however, there is a deficit in data regarding mid-term outcomes. The purpose of this study was to evaluate the clinical and radiographic outcomes following reverse total shoulder arthroplasty with latissimus dorsi transfer with mid-term follow-up. We hypothesized significant improvement in external rotation and shoulder functionality for patients with preoperative external rotation lag. We retrospectively reviewed patients who underwent reverse total shoulder arthroplasty with latissimus dorsi transfer. Preoperative and postoperative changes in range of motion were assessed. American Shoulder and Elbow Surgeon Score and the Simple Shoulder Test were used to evaluate changes in shoulder function while pain scores were assessed using the Visual Analog Scale (VAS). Radiographs were reviewed for rotator cuff arthropathy, fatty infiltration, scapular notching, baseplate loosening, and osteolysis. We reported frequency and mean ± standard deviation for categorical and continuous variables, respectively. Means were compared using the paired Student's t-test and proportions using the Chi-square test. Fifteen patients met the inclusion criteria. The mean age of the cohort was 71.7 ± 8.4 years (range 51.2-87.8 years) with a mean follow-up of 6.3 ± 4.1 years (range 1.0-14.5 years). Reverse total shoulder arthroplasty with latissimus dorsi transfer improved external rotation (-7 ± 21.3° to 38 ± 15.8°; p value = 0.001). There was no statistically significant difference regarding forward flexion (116.3 ± 45.4° to 133.7 ± 14.7°; p value = 0.17) and internal rotation (T12 to L2; p value = 0.57). The procedure led to an increase in American Shoulder and Elbow Surgeon Score scores (37 ± 19 to 62 ± 22; p = 0.005) and Simple Shoulder Test scores (2 ± 2 to 6 ± 3; p value = 0.001) with a significant reduction in Visual Analog Scale scores (5 ± 3 to 2 ± 3; p value = 0.022). The procedure corrected external rotation lag in 10 patients. Radiographically, rotator cuff arthropathy was found to be grade 3 in two patients, grade 4 A in four patients, grade 4B in eight patients, and grade 5 in one patient. On postoperative imaging, scapular notching was found in six patients (40%). Twelve patients had cortical humeral erosion at the site of the latissimus dorsi transfer. Only one patient experienced a shoulder-related complication which was aseptic baseplate loosening and required a revision reverse total shoulder arthroplasty with allograft. In this study, patients undergoing reverse total shoulder arthroplasty with latissimus dorsi transfer experienced improvements in range of motion, functional scores, and pain at mid-term follow-up. The shoulder-related complication rate was low.Level of evidence: IV; Case series.